I11-High Resolution Powder Diffraction
|
Nataliya L.
Gulay
,
Hai
Lin
,
Batoul
Almoussawi
,
Cara J.
Hawkins
,
Manel
Sonni
,
Marco
Zanella
,
Troy D.
Manning
,
Luke M.
Daniels
,
Matthew S.
Dyer
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[36629, 37989]
Open Access
Abstract: During the exploration of the interface between the known structures of perovskite Y2NiTiO6 and hexagonal layered Y2CuTiO6, we have discovered the new phase Y10NixCu1–xTi4O24 (x = 0, 0.5, 1). The structure of Y10CuTi4O24 was solved by means of single-crystal X-ray diffraction, which revealed a layered monoclinic structure, with the space group C2/m, a = 12.2405(1), b = 5.8643(1), c = 7.1729(1) Å, β = 107.083(1)°. The structures of three Y10NixCu1–xTi4O24 (x = 0, 0.5, 1) phases were also refined based on high-resolution powder X-ray diffraction data. Substitution of Cu for Ni causes only minor changes in lattice and atomic parameters. The new phase is related to known Y5Mo2O12-type structures with an extra atomic position occupied by Ni/Cu in the structure of Y10NixCu1–xTi4O24 (x = 0, 0.5, 1). The high-resolution powder X-ray diffraction data revealed peak broadening for the reflections with l = 2n + 1 corresponding to stacking faults originating from the layered structure of Y10NixCu1–xTi4O24. Y10NixCu1–xTi4O24 (x = 0, 0.5, 1) were characterized with respect to their magnetic and optical properties.
|
Jul 2026
|
|
I11-High Resolution Powder Diffraction
|
Diamond Proposal Number(s):
[37989]
Open Access
Abstract: We report the experimental discovery of Li7Si2S7I0.89Cl0.11, a triclinic (P-1) analogue of the recently discovered monoclinic (P21/n) Li7Si2S7I (LSSI), which retains the high computationally predicted Li+ ion conductivity of LSSI. Li7Si2S7I0.89Cl0.11, which is effectively a polymorph of LSSI, maintains the same ordered anion packing based on the packing of spheres in NiZr intermetallic, however demonstrates a distinct ordering of the Si4+ framework-forming cations. While both structures feature Si2S7 dimers within hexagonal close-packed (hcp) anion motifs, their different arrangement in the triclinic material results in the alternating stacking of silicon-free and silicon-rich layers. Li7Si2S7I0.89Cl0.11 has an additional Li+ position compared to LSSI, sixteen in total, which maintains the large number of redundant low energy pathways favourable for superionic conduction. Thus, Li7Si2S7I0.89Cl0.11 has a predicted ionic conductivity derived from molecular dynamics simulation of the experimentally measured structure of 0.019(7) S cm–1 and theoretical activation energy for bulk Li+ ion transport of 0.16(4) eV, within error of those of monoclinic LSSI. These results demonstrate the structural resilience of the ordered S2–/I– anion net to changes in cation positions and crystal system, further exemplifying the ability of the net to afford diverse low barrier Li ion transport pathways and thus generate a predicted superionic conductivity. Polymorphism is generally thought to have a profound impact on ion transport, however the computational results here suggest that there are privileged anion frameworks with an intrinsic robustness to changes in cation distribution where superionic transport can persist.
|
Jun 2026
|
|
I11-High Resolution Powder Diffraction
|
Alexandra
Morscher
,
Lucia
Corti
,
Samuel L.
Goodwin
,
Andres
Acin-Lalanza
,
Matthew
Wright
,
T. Wesley
Surta
,
Ruiyong
Chen
,
Matthew S.
Dyer
,
Frédéric
Blanc
,
Luke M.
Daniels
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[37989]
Open Access
Abstract: Sulfide lithium argyrodites are a key materials family that are studied as solid electrolytes in commercial all-solid-state batteries (ASSBs), while their oxide analogues remain relatively unexplored. This study presents the discovery of Li7TiO5X (X = Cl–, Br–), the first lithium argyrodite materials in which a transition metal is used as the framework-forming cation, expanding the chemical space that is accessible for oxide argyrodites. Incorporation of Ti4+ enables the lithium content to be maximized to 7 Li+ per formula unit. Interestingly, even with the high lithium content, Li7TiO5Cl retains a Li+ site disordered cubic F4̅3m structure at room temperature with Li+ occupancy of the T5, T5a, and T3 positions, and exhibits an ionic conductivity of 2.2(2) × 10–6 S cm–1 with the lowest reported activation energy (0.36(2) eV) for bulk Li+ ion transport in an oxide argyrodite. Conversely, Li7TiO5Br adopts the same F4̅3m symmetry at room temperature but with an ordered arrangement of Li+ positions via full occupancy of the T5a and T3 positions, and thus has an ionic conductivity that is 3 orders of magnitude lower (∼10–9 S cm–1) and a much higher activation energy (0.58(2) eV) than Li7TiO5Cl. Order–disorder behavior is observed below 250 K in Li7TiO5Cl, where a Li+ site ordering pattern is observed that is distinct from Li7TiO5Br and all sulfide argyrodites, yielding a tetragonal symmetry (I4̅) for only the second time to date in the argyrodite structure type. This unique order–disorder behavior, alongside the ability to incorporate transition metal cations within this material family emphasizes the potential to access much greater structural diversity via the expansive chemical space that is available for exploration in oxide argyrodites.
|
Jun 2026
|
|
I11-High Resolution Powder Diffraction
|
Brinda
Kuthanazhi
,
Debalina
Banerjee
,
Dmitry
Maslennikov
,
Andrij
Vasylenko
,
Jan P.
Scheifers
,
Cara J.
Hawkins
,
Daniel
Ritchie
,
Craig M.
Robertson
,
Marco
Zanella
,
Troy D.
Manning
,
Luke M.
Daniels
,
Marina R.
Filip
,
Matthew S.
Dyer
,
Laura M.
Herz
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[37989]
Open Access
Abstract: We explore multiple-cation chalco–halide phase fields evaluated by their synthetic accessibility using machine learning models. Exploratory synthesis guided by computational tools leads to the discovery of two new compounds; CuSn2SI3 and Cu0.35Sn5.29S2I7, their structures, and electronic and optical properties are reported herein. This is the first report of a stable quaternary compound in the Cu–Sn–S–I phase field. The two new compounds show related crystal structures where Sn4S2I4 layers are a common structural motif in both. These Sn4S2I4 layers are connected by Cu2I2 layers and disordered Cu–Sn–I layers, forming the three-dimensional structures of CuSn2SI3 and Cu0.35Sn5.29S2I7 respectively. Electronic band structure calculations using density functional theory show the presence of a direct band gap in CuSn2SI3 and suggest anisotropic transport, in line with the layered structure of the compound. A mixture of the two compounds with ∼86% CuSn2SI3, shows a band gap in the visible region, close to 2.1 eV and a significant photo-induced charge carrier mobility of ∼1.3 cm2 V−1 s−1. This demonstrates Cu–Sn chalco–halides can form a promising phase space to explore for solar absorber materials, with further design and tuning of band gap.
|
Mar 2026
|
|
I19-Small Molecule Single Crystal Diffraction
|
Cara J.
Hawkins
,
Batoul
Almoussawi
,
Jan P.
Scheifers
,
Manel
Sonni
,
Aeshah A.
Almushawwah
,
Troy D.
Manning
,
Marco
Zanella
,
Craig M.
Robertson
,
Luke M.
Daniels
,
Tim D.
Veal
,
John B.
Claridge
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[36629]
Open Access
Abstract: The exploration of higher-dimensional chemical phase spaces and the synthesis of novel compounds can be achieved by applying a multiple-anion approach to materials discovery. The ability to combine and tune the stoichiometry of anions in a material can enable enhanced control of both the physical and electronic structures, providing a strategy for the modification of the properties of new materials being developed for a variety of applications, including solar absorbers and thermoelectrics. Here, we report the synthesis of Cu7.62Bi6Se12Cl6I, a quadruple-anion (Se2–, (Se2)2–, Cl–, I–) material within the Cu–Bi–Se–Cl–I phase space. Crystal growth reactions yield black, needle-like crystals, which exhibit a highly anisotropic and complex structure containing the four distinct anion types, solved from single-crystal X-ray diffraction data. Compositional analysis confirms the complex material stoichiometry, and a low band gap of 0.94(5) eV is measured to understand the potential for solar-absorbing applications. Cu7.62Bi6Se12Cl6I has a low thermal conductivity of 0.25(2) W K–1 m–1, which is attributed to multiple structural features via analysis of experimental heat capacity data and is achieved through the diversity in bonding that is accessed through the combination of four different types of anion.
|
Feb 2026
|
|
I11-High Resolution Powder Diffraction
|
Open Access
Abstract: The first reported phase in the Y2O3–NiO–TiO2 chemical space, the Y2NiTiO6 perovskite undergoes a temperature-induced order–disorder transition. Above ∼1700 K, it adopts the structure of a disordered CaTiO3-type orthorhombic perovskite with a = 5.26939(2), b = 5.60367(2), and c = 7.58137(3) Å, with the B site uniformly occupied by 0.5Ni+0.5Ti. Below this temperature, Y2NiTiO6 adopts rock-salt ordering of the transition metals in a monoclinic unit cell (a = 5.26695(2), b = 5.60164(2), c = 7.57493(2) Å, β = 90.4940(2)°) with 0.9/0.1 ordering of the B site. Ordering of Ni and Ti changes the magnetic properties from spin-glass behavior in the orthorhombic phase to antiferromagnetic order (TN = 17 K) for the monoclinic phase, while the optical properties of both phases remain unchanged across the transition.
|
Oct 2025
|
|
I11-High Resolution Powder Diffraction
|
Jungwoo
Lim
,
Manel
Sonni
,
Luke M.
Daniels
,
Mounib
Bahri
,
Marco
Zanella
,
Ruiyong
Chen
,
Zhao
Li
,
Alex R.
Neale
,
Hongjun
Niu
,
Nigel D.
Browning
,
Matthew S.
Dyer
,
John B.
Claridge
,
Laurence J.
Hardwick
,
Matthew J.
Rosseinsky
Diamond Proposal Number(s):
[31578]
Open Access
Abstract: LiNiO2 positive electrode materials for lithium-ion batteries have experienced a revival of interest due to increasing technological energy demands. Herein a specific Ti4+ substitution is targeted into LiNiO2 to access new compositions by synthesizing the LiNi1–xTi3x/4O2 solid solution with the aim of retaining Ni3+. Compositions in the range 0.025 ≤ x ≤ 0.2 form nanocomposites of compositionally homogeneous ordered R
m and disordered Fm
m rock salt domains as observed via X-ray and neutron diffraction, and STEM. The disordered rock salt domains stabilize the ordered structure to provide excellent structural reversibility via the formation of coherent interfaces during cycling and enable deep delithiation using a constant voltage charging step without structural degradation. The detrimental structural phase transitions associated with the poor cyclability of LiNiO2 are suppressed to yield a low strain positive electrode material with high capacity retention that offers high-rate capability even under increased cell electrode mass loadings. The composition x = 0.075 (LiNi0.925Ti0.05625O2) affords a 93% capacity retention after 100 cycles (100 mA g−1) and demonstrates high reversible capacities of 125 mAh g−1 even under rates of 3200 mA g−1. LiNi0.925Ti0.05625O2 exhibits exceptional performance at electrode mass loadings (13.6 mg cm−2) comparable to those required for commercial cell applications.
|
Jul 2025
|
|
I11-High Resolution Powder Diffraction
|
Diamond Proposal Number(s):
[23666]
Open Access
Abstract: Perovskites offer vast flexibility in tuning subtle distortions in their structures through their innate ability to host a wide range of compositional combinations. Minor changes in composition can dramatically influence the properties observed through structural distortions such as octahedral tilting. In addition to understanding their properties, in magnetic materials, the magnetic structure is also tied to the nuclear structural distortions and can have more complex behavior with changing composition. In this work we report on the magnetic properties, and nuclear and magnetic structures of the solid solution (1 – x)BiFeO3 – (x/2)Ca2Fe4/3W2/3O6. With the exception of BiFeO3, all samples show a weak ferromagnetic behavior arising from spin canting. We find that despite only one structural phase transition occurring from R3c to Pnma in this solid solution, the magnetic phase diagram is far more complex, with four distinct magnetic phases occurring in the compositional range 0.1 < x < 1. Using a combination of neutron and X-ray diffraction, we find that a crossover between long and short Fe–O bond lengths and divergence of Fe–O–Fe bond angles with composition drive the changes in magnetic structure and can be correlated to the resulting magnetic properties.
|
Jul 2025
|
|
I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
|
Diamond Proposal Number(s):
[36629, 31578]
Open Access
Abstract: Apatites are an important mineral-based material family with huge chemical and structural diversity. They were recently implicated in the claims of high-temperature superconductivity in materials labeled LK-99 that display complex phase mixtures containing Pb, Cu, phosphate, and oxide components. We report Cu-substituted lead apatite solid solutions Pb10–xCux(PO4)6O that display two distinct compositional ranges differentiated by structural ordering. For x > 0.5, we observe substitution in the apatite archetype structure, whereas for x < 0.5, we find an apatite superstructure with coupled anion and cation ordering. The 1 × 1 × 2 superstructure in the noncentrosymmetric space group P6̅ (no. 174) for Pb10–xCux(PO4)6O with x < 0.5 exhibits a unique oxygen ordering motif in the hexagonal channels and selective Cu substitution only on two out of seven Pb sites. At x > 0.5 in Pb10–xCux(PO4)6O, Cu cations are introduced onto all Pb sites, which triggers the transition to the archetypical apatite structure, reflecting the coupling of the core structural components of the apatite framework in the ordering pattern.
|
Apr 2025
|
|
I11-High Resolution Powder Diffraction
|
Matthew J.
Rosseinsky
,
Moinak
Dutta
,
Angelos B.
Canaj
,
Tilen
Knaflič
,
Christopher M.
Collins
,
Troy D.
Manning
,
Hongjun
Niu
,
Luke M.
Daniels
,
Aikaterini
Vriza
,
Luke A.
Johnson
,
Bhupendra
Mali
,
Yuri
Tanuma
,
Todd Wesley
Surta
,
John B.
Claridge
,
Neil
Berry
,
Denis
Arčon
,
Matthew S.
Dyer
Open Access
Abstract: We report the synthesis, structural characterization and magnetic properties of K3coronene, and demonstrate a computational screening workflow designed to accelerate the discovery of metal intercalated polycyclic aromatic hydrocarbon (PAH), a class of materials of interest following reports of superconductivity, but lacking demonstrated and understood characterised materials compositions. Coronene is identified as a suitable PAH candidate from a library of PAHs for potassium intercalation by computational screening of their electronic structure and of the void space in their crystal structures, targeting LUMO similarity to C60 and the availability of suitable sites to accommodate inserted cations. Convex hull calculations with energies from crystal structure prediction based on ion insertion into the identified void space of coronene suggest that the x = 3 composition in Kxcoronene is stable at 0 K, reinforcing the suitability of coronone for experimental investigation. Exploration of reaction conditions and compositions revealed that the mild reducing agent KH allows formation of K3coronene. The structure of K3coronene solved from synchrotron powder X-ray diffraction features extensive reorientation and associated disorder of coronene molecules compared with the parent pristine host. This is driven by K+ intercalation and occupation of sites both within and between the coronene stacks that are partially retained from the parent structure. This disruption of the host structure is greater when three cations are inserted per coronene than in reported metal PAH structures where the maximum ratio of cations to PAH is 2. Superconductivity is not observed, contrary to previous reports on Kxcoronene. The expected localised moment response of coronene3- is suppressed, which may be associated with the combination of extensive disorder and close coronene3- - coronene3- contacts.
|
Dec 2024
|
|
